256962591 has 16 divisors (see below), whose sum is σ = 393813600. Its totient is φ = 165400704.

The previous prime is 256962581. The next prime is 256962613. The reversal of 256962591 is 195269652.

It is a happy number.

256962591 is a `hidden beast` number, since 2 + 56 + 9 + 6 + 2 + 591 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-256962591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256962581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 163306 + ... + 164871.

It is an arithmetic number, because the mean of its divisors is an integer number (24613350).

Almost surely, 2^256962591 is an apocalyptic number.

256962591 is a deficient number, since it is larger than the sum of its proper divisors (136851009).

256962591 is a wasteful number, since it uses less digits than its factorization.

256962591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328215 (or 328209 counting only the distinct ones).

The product of its digits is 291600, while the sum is 45.

The square root of 256962591 is about 16030.0527447666. The cubic root of 256962591 is about 635.7552680681.

The spelling of 256962591 in words is "two hundred fifty-six million, nine hundred sixty-two thousand, five hundred ninety-one".